Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é a média de matrículas da Dickinson College?
 ###Tabelas: CREATE TABLE singles_runner-up (singles_runner-up_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament VARCHAR, Surface VARCHAR, Opponent in the final VARCHAR, Score VARCHAR) CREATE TABLE list_of_member_schools (list_of_member_schools_id AUTO_INCREMENT PRIMARY KEY, School VARCHAR, Team Name VARCHAR, Town VARCHAR, County VARCHAR, School Enrollment (2008–10) INT, Football? VARCHAR) CREATE TABLE w109 (w109_id AUTO_INCREMENT PRIMARY KEY, Model VARCHAR, Chassis code VARCHAR, Production time VARCHAR, Number built INT, Engine VARCHAR) CREATE TABLE tennent's_scottish_cup (tennent's_scottish_cup_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Opponent VARCHAR, Venue VARCHAR, Result VARCHAR, Attendance INT, Scorers VARCHAR) CREATE TABLE american_division (american_division_id AUTO_INCREMENT PRIMARY KEY, Institution VARCHAR, Location VARCHAR, Nickname VARCHAR, Enrollment INT, Established INT)  
SELECT AVG Enrollment FROM american_division WHERE Institution = dickinson college